[sheepdog] [PATCH] sheep: add simple_store driver again

[MORITA Kazutaka]

At Fri, 24 Aug 2012 15:28:07 +0800,
Liu Yuan wrote:
> 
> I think simple_store.c itself won't cause confusion. 'default store'
> will instead cause greater confusion.

The reason I think 'simple' is not good is that we had a 'simple'
driver before which had a completely different data layout.  There may
be some users who still use a simple driver with old sheepdog version.
If they upgrade to the latest version, it leads to complete data
corruption.

> No, this won't change the data layout of farm at all. Just adding
> another .stale file directory, which is useless after cluster becomes
> stable. With .stale, old .farm directory will be solely used for storing
> snapshot objects, which is also relevant to ordinary data objects in
> working directory.

After all recovery completes, it is true.  Okay, it looks good to me.

Thanks,

Kazutaka